Forbidden Passion
by SailorMoonFanForever
Summary: Usagi is dating Motoki but cheats on him one night with Mamoru. A heated night of forbidden passion turns their lives upside down and the guilt plagues them afterwards. But will that one night have more consequences than they ever imagined? Will their love survive the judgement that soon follows? UsaxMamo.
1. Chapter 1

**AN: Hey this is my first Christian Mamoru and Usagi fanfiction. I'm not sure how this will turn out, we will see. If this does not interest you, please don't read. I will be posting non-religious fanfics later on. Thank you and please enjoy. **

Mamoru and Usagi were good friends. Freshman year, when the two had just meet, Mamoru had made passes at Usagi constantly flirting with her until eventually they went out for a few weeks before it ended abruptly when she found out that he was cheating on her. After months of playing the field, Mamoru tried to get Usagi back, but it was too late, she was already dating Motoki. Motoki was a very devote Christian. Usagi herself, along with her friends were also Christians, but not at the same level as Motoki. Mamoru was an entire other story. While he claimed to be a Christian, his actions did little to show others of his faith.

Usagi cared for Motoki deeply but there was just no chemistry between the two of them. They barely kissed on the cheeks and she was losing her resolve around Mamoru. He was always hanging around and flirting with her trying to win her back until one day she couldn't take it any longer.

Mamoru had been her first love, and even though he had betrayed that love when he cheated on her, she knew that she would always love him. He was a good guy that truly cared for her she believed, and he was so hot! While she dated Motoki, she tried hard to focus on him and not how Mamoru made her feel. He was dangerous and flirty, two qualities that Motoki lacked. He was just… safe.

Now, being that she was a Christian, that **should** have been what she was looking for, but it wasn't. Neither boy had actually kissed her before and that made her blush. She was sixteen and never had been kissed even though she had had two boyfriends. Even with Mamoru's flirty side, he had never kissed her on the lips. She couldn't wait for it. She truly wanted him to be her first kiss. She felt so attracted to him.

So, that day when Mamoru had come up to her, her defences had been broken. He had told her that he was serious about them getting back together. After school the two had made it to his place as he lived by himself after getting out of child services. Both his parents had died when he was very young. Usagi knew she was breaking her parent's rules right now, by not coming home right after school, but at the moment she didn't care, she just wanted to be with Mamoru after all this time apart.

The two ended up in his bedroom. At first they were just talking. She asked him if he was really over his flirtatious ways and he had assured her that he was and that he had only truly ever loved her. He said that he only cheated on her out of fear for the strong emotions and attraction he had for her. Strong emotions and attraction which equalled trouble the moment their lips would touch.

Usagi was sitting on his bed when he faced her. "I am really sorry that I caused you pain, Usako," he said calling her by the nickname he had given her on the first day they'd met. It had been instant chemistry for both of them.

She smiled, believing the truth behind his words. "It's okay. I forgive you."

He smiled back and gently cupped his hand around her face. "I've missed you so much," he murmured as his face grew dangerously close to her own.

This was it, Usagi thought. She knew that she was cheating on Motoki and things hadn't officially ended between them, but surely he had to know that things weren't going anywhere right? He never showed her how he felt other than in a short hug and hand holding here and there. She wanted the guy she was with to show her his feelings with more passion and excitement. That had been her second mistake.

She got passion alright when Mamoru closed the distance between them and their lips touched. It was soft and sweet. The two pulled away for an instant to look into the other's eyes before coming back together in a lust for each other. Both knew what was happening. Both knew that they shouldn't be doing this, that not only were they cheating but they were going against their faith by doing what they were about to do before marriage. Still, that didn't stop the other.

"We shouldn't be doing this," Mamoru panted lightly between kisses. Regardless of his words, or his brain telling him to stop, he lowered his head and captured her lips again. Usagi pulled slightly away for a moment so that she could look into his eyes.

"But I want to. Don't you?" she asked suddenly concerned.

Mamoru nodded. "Of course, but what about…?" his words were interrupted by her lips on his.

"He doesn't understand me and my feelings like you do."

Usagi kissed him again, trying to convince him she was telling the truth. She was for the most part… she cared for Motoki but it was true, he barely touched her before pulling away let alone kiss her or do other stuff. She wanted to be able to show the man she loved her feelings. She'd loved Mamoru since the moment she saw him and even when dating Motoki, if she were honest with herself, she had still been in love with Mamoru.

Mamoru, not wanting to lose his chance to finally be with the girl he loved, said nothing, but kissed her soundly, pulling her unto the bed with him. Usagi lightly fell on top of him as the two began unbuttoning the other's shirt. Each blushed slightly while doing this, both knowing that after that night their lives would change forever. But it was for the better, right?

"You sure?" he asked one final time, his eyes slowly falling to her lacy bra. She smiled into his lips as she kissed him with such a passion she didn't know she had inside her.


	2. Chapter 2

Usagi's eyes opened as the sunlight streamed into the otherwise dark room. The room was fairly bare she noticed as she looked around, not much to decorate it and there were no pictures on the walls. It actually felt cold and empty and Usagi instantly felt sympathy for Mamoru. Mamoru. Her head turned on the pillow and she faced him. His eyes were closed and he looked so peaceful as he lay asleep. She smiled. Then her mind focused on the night before. They had actually had sex. Her stomach instantly was met with a wave of nausea. She had broken her pact with God and all the promises she knew she was supposed to keep until marriage. How could they have allowed that to happen? Sure she had wanted the passion, she had naively thought that she could have the passion without the sex, little had she known the fire she would feel the moment he kissed her lips. And that is exactly what she had felt. A fire she had not even known possible to exist, in her sheltered pure life, had come over her body leaving her helpless against the throws of passion that soon followed. With every touch he had sent her into a world of ecstasy.

She instantly regretted doing it. She didn't regret doing it with Mamoru, no she loved him dearly, she always had, but she just regretted doing it before they got married. She wasn't even sure he wanted that from their relationship, she mentally berated herself. How could she have been so careless? How was she supposed to face him now after they had done that to each other? How was she supposed to face her parents who had raised her better than that and to resist such temptations? How was she supposed to face Motoki after cheating on him like that? Not only had she kissed Mamoru but she had committed a life binding act that was sacred in her beliefs. How could she face God now? Her head was spinning.

Mamoru shifted ever so softly as his eyes opened. Those mystical blue eyes had captured her heart the moment they had met. He smiled at her. His mind focused solely on her and how much he loved her. He was not feeling the same type of regret Usagi was. Then again, his faith was not as strong as Usagi's. He felt he could remain in his faith even after committing this act and felt no remorse for it. Usagi gave him a weak smile. He instantly knew what was going through her mind, and even though he did not feel the regret himself, he knew that she was feeling it enough for the both of them. That is why he loved her so much. She had such strong beliefs and morals. He still felt that way regardless of what they had done the night before.

"Usako," he murmured as he leaned over on his shoulder to kiss her lips. It was a sweet kiss lacking the passion and heat from the night before but she smiled into it non-the-less. In some way, on some level, she had been afraid of rejection after the previous night's actions. But she really should have known better than to think that of Mamoru. She was just feeling overwhelmingly insecure.

"Mamo-chan," she said softly back, her heart racing a mile a minute. She really couldn't linger much longer. They had school and she had to get back home before her parents woke up for work.

"I… I should get going," she said quickly, stuttering on the words. His eyes widened and his eyebrow rose in question.

"You want to leave?" he asked quietly, his eyes giving her pleading puppy dog eyes.

She nodded. "I… need to get home before my parents wake up and I… I need to process what happened," she said truthfully. "I just need time."

While her words hurt Mamoru, piercing his heart in tiny slivers, he nodded. He understood that there would be emotional repercussions for their sinful behaviour. Once again even though he didn't feel it, he did not hold anything against her for feeling what he knew he should be feeling right now as well. He lifted his body up and his perfectly chiselled chest was in her sight again. She unknowingly licked her lips, the action not lost on Mamoru. A smirk appeared on his lips but he didn't say anything. She quickly turned her body and rose to her feet standing just beside the bed, her back towards him. He was surprised and thrilled that she hadn't insisted he look away when she stood, her naked form from her back view accessible once again to his eyes. He savoured and etched the memory in his mind. He knew that it would be a long time before he saw her beautiful naked body again. She had wanted to, in the moment he was sure, have sex with him, but he also knew that she had known better than to do that. While they had broken their own pacts with God, he knew that she would not take it lightly to allow it to happen again.

She lowered her naked form to the ground, her front blocked from his vision. She picked up her recklessly thrown clothes and silently dressed. Then when she was clothed, she turned and faced him. He was still in bed, only his lower half covered by the silk black sheets; he looked so sexy and irresistible. Her body began to heat up again and she knew she had to get out of there before she lost her willpower again. Now that their bodies had been joined in such a way she longed to be with him again. She knew it would be too wrong to allow it to happen again. As it was she was overcome with guilt and that thankfully fuelled her exit.

She smiled at him lovingly despite the sickness in her stomach. She loved him so much despite the regret. She needed him to know that. She walked over to his side of the bed and claimed his lips in a short kiss. She gently caressed his face with her soft fingers.

"I love you," she whispered. "I always have, always will. Last night doesn't change that," she murmured against his face their noses touching, her eyes closed as she breathed in his scent.

"I love you too, Usako," and although the feelings had been expressed the night before, and she had known how he felt through his passion, it felt good to actually hear those words being uttered from his lips.

Usagi pulled away and began walking out of his bedroom. Standing in the doorway she turned around. "See you at school?" she asked softly. He nodded and she smiled back at him before leaving him.


	3. Chapter 3

**AN: Sorry for the long update -5 months yikes! I will try and update quickly from now on. I have so many ideas for this fanfiction! Enjoy.**

Usagi arrived at her house, standing still before the large wooden doors that were a protection for her. But the walls meant to hold her in hadn't worked as well as they should have, they hadn't protected her from the anguish she was going through right now. She sighed deeply as she reached for the door knob and entered her key. Turning it ever so slightly, she opened the door and tipped-toed inside. She let out the breath she had been holding as the front door shut and her parents didn't notice her late night/early morning entrance. For this alone she was grateful. Maybe she wouldn't even have to tell them. She knew that not telling them was a lie by omission and was still a sin but she couldn't bear to see the looks of disappointment on their faces if she told them. She couldn't handle that on top of everything she was going through right now.

She quickly went upstairs and showered. She spent more time than necessary in there, letting the warm water run down her body, almost as if she was willing it to cleanse her soul. She knew that was not the answer. After getting dressed she sat down on her bed, cross legged and closed her eyes. She needed to ask for forgiveness before she continued on with her day. She knew that even if she prayed, she would still feel guilty for along time, but she knew she needed to let her Saviour's blood cleanse her of her sin. That was the only way. She said the apology silently, praying the words in her head.

_Lord, I know that what I did was wrong. I know we shouldn't have done it. I see now why you say sex is meant for marriage as it joins two people together in such an amazing way. I can only regret not listening to the warnings your Spirit was telling me and ask for your forgiveness. Please forgive me and cleanse me of all my sins. Please give me the strength to avoid temptation again and please give me the courage to tell Motoki the truth. In your holy name I pray, amen._

The morning passed without any confrontation from her parents or from Mamoru or Motoki. She hadn't seen either of the guys as she had arrived late to school and hadn't lingered in the halls when changing classes. Lucky for her she hadn't had any classes with either of them that morning. Then afternoon came and Usagi was at her locker getting her lunch when her best friend Minako came up to her. She opened her locker beside Usagi's and got her lunch out as well. Closing her locker she turned to Usagi, leaning her back on her locker.

"Hey, Usagi-chan," she said. "I haven't seen much of you lately. Let's go eat together so that we can catch up. The whole gang is there already, I just came to get you."

Usagi nodded and then walked with her friend to the cafeteria. Surely enough everyone they knew was there: Makoto, Rei, Ami, Motoki, and Mamoru. She gulped. Mamoru. Motoki. Her heart raced. The two of them were there together. Her head began to spin with guilt but Minako yanked her arm towards the table before she had time to use her sudden dizziness as an excuse to get out of there.

Motoki stood up from his seat the moment he saw her. He beamed as he reached over to kiss her lightly on the lips, hardly anything in comparison to the heat of the night before with Mamoru. She let him but didn't kiss him back. She was so very unsure of all the feelings she was feeling that she didn't know what to think or do. She'd had sex, for the very first time in her life, and it had been before she got married. No one could know. They just couldn't. No one in her family or group of friends would understand or condone her actions. It would forever be her dirty hidden secret, hers and Mamoru's. Her mind focused on this burden she would forever have to bear and she was glad that it was at least with Mamoru and that she didn't have to bare this shame alone.

"Hey, Girlfriend," he said as he pulled apart, still grinning.

"Hi, Motoki," she said softly, not really feeling the love. Luckily he didn't notice but sat back down and resumed eating. Usagi remained standing, unable to force herself to sit down.

Usagi turned and looked over at Mamoru. Their eyes met, his blue eyes searching hers for some kind of response about the night before. She didn't say anything but just stared and let her mind wander unto thoughts she best soon forget. Her body heated up as thoughts filtered into her mind on everything that had happened the night before and the heat that had soared through them. Her mind drifted back to his bare chest, his tender touch, and the taste of his kisses. Then she realized suddenly what she thinking about and that she was staring and couldn't help but blush fiercely.

"Mamoru," she stated his name before looking away and breaking their connection.

Mamoru gave her one more hopeful glance even though she wasn't looking before jumping up. He quickly grabbed his things and walked right past her as he hurried out of the cafeteria. Usagi stared after him for a second, utterly stunned at his reaction.

"What was that all about?" Motoki wondered out loud.

Usagi shook her head, lying, even though she knew exactly why he had left. She felt it too. Guilt. They should have waited, should have controlled their feelings until they were married, or at least older. Surely they should not have done that while she was still dating Motoki. The lying had come so naturally to her that she was shocked. The sins were piling up now as lies fell into that increasing pile to try and cover up her shame.

Usagi felt hot tears form behind her lids. She tried to blink them back but couldn't. A few trickled down her cheeks. Motoki stared at her, as well as every one else at the table, concern in their eyes. Was he having second thoughts about last night? He had seemed hurt and sad… maybe even a bit angry? But why? He had been so happy this morning. Had her sudden exit caused him to doubt her love? Was it because he thought that she was going to stay with Motoki? She wasn't sure what was going to happen herself, so she couldn't really blame him for wanting to know, but still. She needed to see him! Her heart ached seeing him like this.

"Mamoru," she said under her breath as she ran away from the table, away from Motoki, and towards Mamoru's disappearing form.

"Mamoru!" she called once she had caught up. He turned, now in the hallway, and stared at her. The moment his eyes saw her tears, his heart broke, and he forgot about all the things that had just minutes ago sent him away from her.

"Are you okay?" he asked softly. She ran into his open arms and hugged him tightly, her head nuzzling into his chest. He smiled as he placed his head on top of hers.

"I can't do this, Mamoru! I want to be with you but I don't want to hurt Motoki," she sobbed against his chest. Mamoru gently rubbed her back.

"I know, Usako. I know," he paused and then looked around. Lucky for them, everyone was eating their lunch and the hallway was deserted. Still, it wouldn't be long before Motoki or Minako came looking for her.

"Let's go outside," he whispered into her soft blonde hair. Usagi leaned backwards against his arms looking into his eyes.

"Okay," she said softly, sniffling a few times, moving out of his arms. Still crying softly, she placed her head on Mamoru's shoulder and the two of them headed outside. They walked a good distance, until they were under a secluded tree.

Mamoru pulled her gently down and unto his lap as he sat down. Usagi, who by now had stopped crying and was only sniffling softly, placed her arms around his waist, holding unto him. Mamoru looked deep into her eyes and slowly lowered his head towards her. He stopped just inches apart from her lips, his black bangs falling sexily over his eyes. Usagi closed the distance and gave him a short but sweet kiss. She pulled apart after a few seconds and blushed, placing her happy but embarrassed face unto Mamoru's chest. Mamoru laughed, a husky sexy laugh, and then placed his head once again on top of hers.

"It will all be okay, Usako," he reassured her. "I promise."

Usagi sighed softly. "I hope you're right, Mamoru, I hope you're right. And that we didn't just make the biggest mistake of our lives."

Mamoru hugged her tightly. "Usagi, you know I love you. Last night was so special for me, I would never regret it," his words sent shivers down her spine.

Usagi leaned against his arms and smiled. "I love you to, Mamo-chan. I have since the moment I saw you. You were my first love. You will always have a special place in my heart."

Mamoru smiled at this and then dipped his head to once again claim her soft sweet lips. After a few minutes of blissful peace, Usagi rested her forehead against his, catching her breath.

"Mamo-chan," she whispered against his lips. He pulled back and gave her a loving look.

"Yes, my Usako," he whispered back, his grin intoxicating her.

"Can you be with me when I tell Motoki the truth about us?" she asked, her eyes softly pleading him.

Mamoru simply nodded before kissing the top of her head. "I wouldn't want it any other way, Angel."

Usagi giggled. "Thanks, Mamoru. I don't want to be with anyone but you," she said the words with such a conviction that all his worries about her not loving him with the same intensity melted away. She was his for life.


	4. Chapter 4

Usagi was leaning back in Mamoru's arms as they remained under the tree in a very cozy position. She reached into her pocket and pulled out her cell phone. She typed a few words before Mamoru's eyes shifted to on her.

"Who you talking to?" he asked gently, his insecurities getting the best of him despite his knowledge that she loved him.

Usagi smiled as she tilted her head up towards him, dropping the phone to her lap. "I just texted Motoki to apologize for leaving so abruptly. I feel so bad that we did what we did last night when I was still dating him. I wonder if that guilt will ever go away. He's going to be heartbroken when I break up with him."

Mamoru nodded in understanding. "He's not a bad guy, although we never hit it off… he means well… I feel guilty too."

Her phone buzzed and she hesitantly picked it back up. She was very much aware of Mamoru's insecurities and she never wanted to hurt him regardless of if it justified or not. She looked at the screen and instantly read the response aloud.

"He says, 'It's alright, I was just worried. Can we talk after school?'" Usagi sighed and began texting again. "He doesn't realize that that is exactly what we need to do," Usagi said as she closed the phone giving all her attention back to Mamoru.

"After last period meet me at my locker and then we will go meet Motoki outside the school together, okay?" she asked, a hint of fear in her voice.

Mamoru nodded. "Sure thing."

The bell rang and the new couple hesitantly moved out of each other's embrace. Usagi stood and silently waited for Mamoru to stand as well. She blocked his way of exit and walked without hurry into his arms and reached up on her tippy-toes to boldly claim his lips. After a minute she pulled away sadly however with a smile on her face.

"I'll see you later," she said very much in love with the man before her. His kisses made her forget all her guilt and calmed her mind. He kissed her quickly once more on her lips before straightening himself and starting to walk away backwards, his eyes following her as he walked.

"Love you," he said just above a whisper, a few steps away from her.

"I love you, too," she said softly as she watched him turn around and dash off to class. Usagi just stood there a moment, her heart racing too quickly to think, before her mind cleared and she made her way to class. After those kisses she hardly cared about her classes.

Lucky for her, she didn't have any classes with Motoki that day. After entering her first class after lunch late she had avoided talking to any of the girls. Then, after class had ended, she had darted off to her next one before any of them could ask her anything about what had happened at lunch. At the moment, she was completely grateful that she had very few classes with the girls. The rest of the day passed all too quickly and before she knew it she was walking towards her locker. Her heart skipped a beat when she saw Mamoru leaning against her locker waiting for her. She picked up her pace, smiling at him even at a distance, not being careful as to if anyone was watching them. Lucky for them, no one was.

"Mamoru," she greeted him happily when she reached his side.

She smiled up at him and couldn't help but want to jump into those strong arms and kiss those soft lips. She mentally ridden her mind of those thoughts. They had to tell Motoki before someone found out and told him. Besides that, she didn't want to have to pretend to still have feelings for him when she had long stopped feeling what little affection had been there.

"Usagi," he greeted back, a huge grin on his face, making him look so incredibly sexy.

When he boldly didn't move, and stood there staring down at her roguishly, she playfully swatted at his waist. He hesitated for a second more before moving, in defeat, away from her locker. She laughed, grabbing her bag and placing her correct books inside. Mamoru already had his books she could tell by the black bag he had by his legs. With a deep sigh full of worry, she closed her locker and reached for his hand. He took it gladly before reaching for his own bag with his other hand. Then they started down the hallway.

"I can't believe we are going to do this to him," Usagi said, panic filling her voice.

Mamoru looked ahead. He didn't want to hurt the guy either but they had to tell him. Usako was his again and _only _his. He was never letting go of her ever again. He knew his heart couldn't take it. He would never again be so stupid to cheat on her. She was his everything and he loved her with all his heart. A smile placed on his lips at his self admittance of this.

"It will be alright," Mamoru said, gently rubbing her hand with his fingers as he held it so tenderly.

Usagi sighed. "I hope you're right."

Then they were at the exit to the school. They stopped just in front of the doors and stared into each other's eyes; both pairs shined with such comforting love without any words being said. Usagi nodded and then he opened the door and the two of them walked hand in hand outside to a waiting Motoki.

Motoki's eyes darkened as soon as he saw the two of them walk out together. He was instantly filled with suspicion. He had always trusted Usagi before, and had never had any reason to doubt her, but looking at the two of them, hand in hand, made all his worries come bubbling to the surface.

"Usagi," he said formally when they reached his side, completely ignoring Mamoru.

"What's this?" he asked, his eyes falling down on their joined hands.

"Motoki," Usagi said and then her voice cracked. She looked like she was about to cry.

"We need to break up," she said quickly and without warning. She said it so fast that Motoki was stunned by the whiplash of it all.

His eyes stared into hers, sadness and regret instantly filling them. "Why?" he asked the words softly.

"Motoki, me and Usagi have decided to-" Mamoru's words were caught off with Motoki's hand in the air in his direction, his eyes focused on Usagi as he glared.

"Don't," he said angrily towards Mamoru. "Usagi please explain," he said his words a tad more gently towards her, despite his clear anger.

"I still love Mamoru," she said softly, tearing her eyes away from Motoki's. She couldn't bare the guilt when she saw the hurt in his eyes. He'd been so faithful to her and she had broken his heart. "I'm sorry."

"I don't understand. How long have you known?" he demanded, his voice raising a notch.

"Since yesterday," Usagi said softly as she stared at her shoes, leaving out the part that it had been in the evening, and that she had woven herself to Mamoru in a way that she had never before even thought of doing.

Motoki huffed loudly. "I can't believe you, Usagi! I thought you loved me… I thought you had moved on! And then you… you… cheat on me? You being unfaithful to me in your mind if nothing else when you're supposed to be a Christian?"

The words came out of him before he could censor the pain he was feeling. He never acted so impulsively or so cruelly. He instantly hated himself for saying those words to her. Mamoru on the other hand finally spoke up again, his eyes glaring back at Motoki viciously.

"Look!" he said loudly. "Usagi apologized and she feels guilty enough trust me! Don't make her feel ever worse by questioning her faith! We _both _apologize for what has happened. We _both _admit that realizing how we feel about each other has come at a bad time but we told you as soon as we could."

Motoki sighed, taking a deep calming breath. "I'm sorry, Usagi. I shouldn't have said that," he said softly. She lifted her head and looked over at him. Tears were in her eyes.

"It's okay," she said quietly. "I'm so sorry I hurt you. We never meant to hurt you."

Motoki nodded. "I know," he said before he stepped backwards, his eyes still focused on them. "I think I should just go now," he said as he turned around. "Goodbye," he called over his shoulder.

Mamoru and Usagi stood there watching as he walked off. Neither could feel guiltier for what they had done even though it was hard to regret it. They seriously had to talk about that… how what had happened between them had really changed their lives. She looked up at Mamoru.

"Can I come over? We really need to talk." Her words pierced his heart with excitement. He nodded and the two of them walked off together.


End file.
